It is well known in the art that the best possible cup of coffee is provided when initially poured immediately or shortly after the coffee has been brewed. Thereafter, successive cups of coffee from the container of coffee, which container is normally maintained under a low heat, deteriorate in taste. This deterioration is a result of chemical reactions at elevated temperatures and evaporation of the water thereby increasing the concentration of undesirable components.
The foregoing problems have been largely overcome by the introduction of instant coffee; for example, "freeze-dried" coffee which may be dispensed in the form of granules from a jar into a coffee cup and the coffee cup simply filled with hot water which dissolves the granules. While fairly drinkable coffee results from this procedure and it certainly overcomes the problem of mixed coffee remaining standing in a pot, the resulting quality is far from that expected by those persons capable of distinguishing fine coffee from the ordinary substitutes.
Substantial improvement in maintaining the quality of coffee after it has been brewed in a pot or container could be realized if some means were provided to prevent undue evaporation and overheating while still maintaining the coffee in the container heated. Normally, actual boiling of coffee after it has been brewed is disastrous. Ideally, the coffee should be kept at a temperature slightly below the boiling point. Any provision for a hermetically sealed container must take into account possible overheating of the coffee which could result in a complete rupturing of the container itself.
Even with the above proposed solution, there still results deterioration of the coffee itself and for providing the ideal cup of coffee, the best solution would be to individually brew coffee for a cup each and every time a cup of coffee is desired. Such would be the optimum system for providing the most satisfactory coffee.